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Question: Answered & Verified by Expert

If the system of equations

x+y+z=2
2 x+4 y-z=6
3x+2y+λz=μ

has infinitely many solutions, then :

MathematicsDeterminantsJEE MainJEE Main 2020 (04 Sep Shift 2)
Options:
  • A  λ+2μ=14
  • B 2λ-μ=5
  • C λ-2μ=-5
  • D 2λ+μ=14
Solution:
2347 Upvotes Verified Answer
The correct answer is: 2λ+μ=14

For infinitely many solutions, all determinants should be zero.

D=11124-132λ=0λ=92

D3=11224632μ=0μ=5

Now check each option 

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